Biomimetic Multicolor-Separating Photonic Skin using Electrically Stretchable Chiral Photonic Elastomers

Abstract

Structural color can be produced by nanoperiodic dielectric structures using soft materials. Chiral photonic elastomers (CPEs) produced from elastic chiral liquid crystal molecules can self-organize into a helical nanostructure, and the chiral nanostructural color can be tuned by stretching. However, the ability to control the separation of biomimetic multicolors for practical applications beyond simple uniaxial stretching of single-colored structures has been limited until now. Here, stretchable CPEs with simultaneous multicolor control, including electrical control, are presented. By engineering the heterogeneous elastic modulus of the CPEs, stretchable and simultaneous multicolor separations from an initially homogeneous color are realized. Electrically stretchable multicolor separation is investigated using a hybrid CPE structure on dielectric elastomer actuators, and multiarrayed color binning and chameleon-like photonic e-skin are further developed for device applications. Moreover, multicolor concealed camouflage switching and control of invisible photonic e-skin are demonstrated. This multicolor control of stretchable photonic systems improves the functionality of various potential photonic applications.

Keywords: biomimetics; chiral liquid crystals; liquid crystal elastomers; multicolor; structural color.